Derby Carbon DH 30I Disc Rim
The Derby DH 30i is the enduro and downhill version of Derby's 30mm carbon rim: the same 34.5mm inner width, hookless 3mm-thick walls and tubeless retention ridges as the TR 30i, in Derby's DH layup with more carbon at the bead and spoke bed, about 590 grams in 29in, 36mm outside and 31mm deep, rated for riders up to 300lb. Made in the USA by a small shop who was building wide carbon mountain rims before the big brands caught on.
This page covers the Derby Carbon DH 30I Disc Rim in 29in. The Derby DH 30i is sold here only inside a wheel we build: choose the hub, spokes and nipples in the configurator and the finished wheel ships from Georgia, laced, tensioned and trued by hand.
Design and construction
The rims are simple in the way good carbon rims are: a shallow hookless section with walls thick enough that a rock strike squeezes the tire rather than cutting it, a bead seat with a retention ridge that keeps a tubeless tire on at 18 psi, and a layup that puts the carbon where the loads are. The 30i takes 2.0 to 2.3in tires happily and 2.6in tires without complaint. The TR layup is for trail and all-mountain; the DH layup adds material for enduro and downhill and is rated for riders up to 300lb.
How it rides
A Derby DH 30i wheel is built to be pointed downhill and left alone. It takes the flat landings and rock gardens that fold alloy downhill rims, the thick walls keep a 2.5in tire from pinching, and the 300lb rider rating tells you how much margin there is. It is heavier than the TR 30i and lighter than any alloy downhill rim. For trail riding the TR 30i is quicker; for enduro, downhill, park and heavy riders, the DH 30i is the Derby rim we recommend.
Specifications
| Wheel size | 29in |
|---|---|
| ERD | 583 (29in) |
| Inner width | 34.5 mm |
| Depth | 31 mm |
| Drillings | 32h |
| Weight | 590g (700c/29in) |
| Material | Carbon Fiber |
| Tire type | clincher tubeless compatible |
| Brake | Disc |
| Profile | Triangle |
| Nipples | External |
| Finishes | black |
This version
This version is the DH 30i in 29in, drilled 32h, about 590g, 34.5mm inside, 31mm deep, disc. Where the same rim is sold in another size or brake type, that is a separate listing with its own page.
This is the disc-brake DH 30i: plain sidewalls, no brake track to wear, a touch lighter. It fits any disc-brake bike and it is the version most of our customers now build; the rim-brake version is a separate listing.
Sizes, fit and compatibility
The Derby Carbon DH 30I Disc Rim comes in 29in and 32h drilling. It is a disc-brake rim. We build the DH 30i on Industry Nine Hydra 2, DT Swiss 350, Hope Pro 5, Onyx Classic and Chris King MTB hubs, usually with Sapim Race, Strong or CX-Sprint spokes or DT Competition and Alpine III, and brass nipples.
Tire range on the DH 30i is 2.3 to 2.6in, tubeless-ready tires only on the hookless bead. Pick downhill or e-bike as your bike type in the configurator and it recommends a spoke count and lacing pattern.
Put it in a custom wheel
Build a custom wheel around the DERBY CARBON DH 30i DISC RIM — the link drops you into our Custom Wheel Program with this rim pinned, ready for you to choose the rest. It is set up for mountain bike, MTB single-speed and fat bike builds.
Spoke head is decided by the hub, not the rim: this rim builds equally well with J-bend or straight-pull spokes, and the configurator only offers the spokes that match the hub you pick.
How Derby tests its rims
Derby Rims, based in Utah, designs its carbon rims in the US and has a partner factory in Asia make them; Derby states its rims were the first carbon rims strong enough for aggressive mountain bikers when it started in 2012. Derby publishes no laboratory impact or fatigue figures; it relies on ride testing. Derby states the Sol Rider line was tested by dozens of extreme MTB riders over 3 years with zero failures, including DH and Enduro racing and 35 foot gap jumps from 2018, and that the first Sol Rider was cracked in 2023 after more than 5 years. The Sol Rider uses Derby's Solstice layup, alternating a US-designed plastic composite fiber UD with UD carbon fiber; Derby states the plastic layers stretch under hard impacts to stop micro-fracturing, and that it was first with 3 mm thick hookless rim walls and bead seat retention ridges.
Derby's warranty is lifetime to the original owner: first replacement free within 5 years of purchase, later replacements 50% off MSRP; secondary owners get 50% off MSRP crash replacement regardless of age. Photos and serial number are required.
Certifications
- Warranty — Lifetime warranty to the original owner: first replacement free within 5 years of purchase, subsequent replacements 50% off MSRP; secondary owners 50% off MSRP warranty/crash replacement regardless of age; receipt, photos and serial number required (source)
Sources on Derby's site:
- Derby Rims - Rim Specs
- Derby Rims - Sol Rider
- Derby Rims - History
- Derby Rims - Terms, Warranty, Returns
- Derby Rims - FAQ
Derby publishes those results; ProWheelBuilder builds the rim into a wheel and does not test it in a lab.
Building it at ProWheelBuilder
Derby makes the DH 30i; ProWheelBuilder is an independent wheel builder in Georgia, not the manufacturer. Spokes are cut from the ERD we measure on the actual rim, the wheel comes up in stages on a tensiometer, and it is stress-relieved and trued before it goes in the box; tape and a valve go on if you ask.
The configurator filters to what fits, crosses out what is not made, and prices the build as you go.
Warranty
Manufacturer's warranty. Derby warrants this product against defects in materials and workmanship. The duration, conditions and claim process are set by Derby and can change without notice, so ask us and we will confirm the current terms before you buy.
ProWheelBuilder. Built into a wheel by us, this part is covered by our own one-year wheel warranty on top of the maker's. For a year we replace broken spokes whatever caused them, and we cover the labor on the wheel - truing, re-tensioning, a rebuild if it needs one. If a rim or hub fails and its maker covers it, we run that claim for you; if the maker says no, you get an eligible replacement rim or hub at 25% off retail. You pay the shipping each way. Wheels built from parts you send us are excluded.
Full terms are on our Policies & Warranty page.
Carbon DH 30I Disc Rim questions
What tire width suits this rim?
34.5mm inside is an enduro width, meant for 2.3 to 2.6in tires. It gives a big casing a square, supported profile so you can drop pressure for grip without the tire folding, which is the whole point of a rim this wide.
DH or TR layup?
DH for enduro, downhill, park, e-bikes and riders over about 200lb; TR for trail and all-mountain where its lighter layup is plenty.
What is the rider limit on the DH 30i?
The maker rates its DH rims for riders up to 300lb, or 135kg.
Is the DH 30i hookless?
Yes. Use tubeless-ready tires and stay under the maximum pressure printed on the rim.
Is the DH 30i e-bike rated?
Yes. Its layup and rider rating suit e-MTB use; pair it with e-bike-rated spokes, which the configurator does when you pick e-bike.
Is ProWheelBuilder the manufacturer of the Derby Carbon DH 30I Disc Rim?
We are not. Derby manufactures the rim; ProWheelBuilder's part is the wheel: measuring, lacing, tensioning and truing it here in Georgia.
Is it tubeless-ready?
Yes. Derby lists the Carbon DH 30I Disc Rim as clincher tubeless compatible; we tape and fit a valve when you choose the tubeless option.
Not sure? Text or leave a voicemail on 470-253-0929 or email info@prowheelbuilder.com — you will be talking to the people who build the wheels.
